Last season, Villas-Boas, 33, took Porto to success in three competitions including the Europa League, but he faces a more daunting task if he is to secure the Champions League title that has so far eluded Roman Abramovich.

Villas-Boas, who worked at Stamford Bridge during Jose Mourinho's time at the club, knows expectations will be high but is optimistic about his chances of success.

"I am confident I can respond to Chelsea's expectations and we can focus on the four trophies that we have to win," he said. "I am pretty much confident that people will like it.

"This is a new leadership, a new way of being, but I think in the end it all ends up in the motivation everyone must feel to continue to win for the club."

He added: "I can understand that Chelsea are obsessed with the Champions League, but Champions Leagues are not won by the best clubs. They are won by clubs that are lucky."

With the arrival of Villas-Boas, there has been inevitable speculation that he will look to take the likes of Hulk, Falcao and Joao Moutinho with him, but Porto president Jorge Pinto da Costa has warned that they will only be sold if release clauses are met.

"If there are termination clauses we have to prepare for the possibility that a player will leave at the value set out, but I am not going to negotiate that price with anyone," he said.